基于Simulink的外调制微波光纤延迟线噪声分析

Noise Analysis of External Modulating Microwave Fiber Delay Line Based on Simulink

微波光纤延迟线利用光纤传输微波信号,具有带宽大、损耗小、质量轻、抗电磁干扰等优势,但也存在噪声较大的问题,从而影响链路的动态范围。本文先建立光路部分与电路部分的噪声数学模型,通过MATLAB中的Simulink建立了外调制微波光纤延迟线的系统仿真模型,完成多种噪声情况下的微波光纤延迟线传输特性仿真,分析了各个主要模块噪声产生的原因以及种类,确定主要噪声源,最后通过仿真模型对外调制微波光纤延迟线进行信噪比分析。

Microwave fiber delay line can provide much wider bandwidth, lower loss, reduced weight and susceptibility to electromagnetic interference in the propagation of microwave signal by optical fiber, while it is generally limited by high noise figure, which affects the dynamic range of system. This paper analyzed noise mathematical models of light circuit and electric circuit, established the modulation models of noises in microwave fiber delay line by Simulink to simulate the property of a microwave fiber transmission delay line. This paper analyzed the causes and types of main noises in a microwave optical fiber delay line and determined the key noise sources. The overall signal-to-noise ratio of a 10GHz external modulating microwave fiber delay line was analyzed finally.